This application makes reference to, incorporates the same herein, and claims all benefits s accruing under 35 U.S.C. xc2xa7119 from my application entitled MICRO WAVE OVEN INCLUDING MAGNETIC FIELD DETECTOR filed with the Korean Industrial Property Office on Jun. 30, 2001 and there duly assigned Ser. No. 2001-38697 and my application entitled MICRO WAVE OVEN INCLUDING MAGNETIC FIELD DETECTOR filed with the Korean Industrial Property Office on Aug. 20, 2001 and there duly assigned Ser. No. 2001-50022.
1. Field of the Invention
The present invention relates generally to a microwave oven provided with a magnetic field detecting device for detecting standing waves.
2. Description of the Prior Art
As well known to those skilled in the art, a microwave oven is an appliance for cooking foods. The intensity of microwaves generated by the magnetron of the microwave oven is determined according to the characteristics of food to be cooked. That is, the characteristics of foot to be cooked, such as the material and shape of food, affect the absorption of microwaves and the amount of absorbed energy, so the microwave oven carries out correct cooking after learning the characteristics of foot to be cooked using a variety of sensors.
The microwaves are formed of a combined electric field and magnetic field, and are radiated from a magnetron through a wave guide to a cooking chamber. In the wave guide, a standing wave is generated by microwaves radiated from the magnetron to the cooking chamber, and microwaves reflected from the cooking chamber to the wave guide.
FIG. 1 is a diagram showing magnetic field detection by the microwave oven. As illustrated in FIG. 1, a conventional electromagnetic field detecting device of a microwave oven for detecting standing waves 30 is formed by grounding one end of an antenna sensor 20 onto the inner surface of the wall of a wave guide 10 through the hole 11 formed in the wall of the wave guide by means of a welding process.
In order to form a predetermined size of a detecting cross section between the wave guide 10 and the antenna sensor 20, the antenna sensor 20 forms a hook shape at its one end. The standing waves 30 are detected by detecting an electromagnetic field, which is generated by the standing waves reflected into the interior of the wave guide 10 and passed through the detection cross section.
As described above, the conventional detecting device of the microwave oven is grounded by welding one end of the antenna sensor to the inner surface of the wall of the wave guide, and is connected to various circuit elements by extending the other end of the antenna sensor out of the wave guide. As a result, there should be carried out processes in which the antenna sensor is welded to the wall of the wave guide and is connected to various circuit elements, so the number of processes is increased and the procedure becomes complicated, thereby hindering the automation of manufacturing and mass production of the microwave oven. Accordingly the productivity of the microwave oven is considerably reduced.
In addition, in the microwave oven with the conventional electromagnetic field detecting device, the position of the antenna sensor secured to the wave guide cannot be accurately controlled, so the cross section formed by the hook portion of the antenna sensor is not constant. As a result, the value of voltage is not accurately detected, so there occurs the problem that the reliability of the detected standing wave data is reduced.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a microwave oven with a magnetic field detecting device, which can be easily fabricated, reduce an error in its assembly, and ensure a certain detection area for detection of standing waves.
In order to accomplish the above object, the present invention provides a microwave oven having a magnetron for generating microwaves and a wave guide for guiding the microwaves to a cooking chamber, wherein a detection opening is formed in one side of the wave guide for allowing a magnetic field generated by standing waves formed in the wave guide to be discharged from the wave guide, comprising a magnetic field detecting device formed on a board mounted on the wave guide for detecting the magnetic field discharged through the detection opening.